423300。 According to the information query of China Postal Code Database, the postal code of Yongxing County, Chenzhou City, Hunan Province is 423300, with the first two digits 42 representing Hunan Province, the third digit 3 representing the postal code, the fourth digit 3 representing the city and county number, and the last two digits 00 representing the mail delivery office and office. Postal code can improve the efficiency of mail delivery, help postal workers quickly and accurately identify the recipient's region and route, and improve the accuracy of mail delivery.